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Animal research

23 - 01 - 2017

Understanding tissue regeneration thanks to the salamander

Researchers have developed a new genomic too to better understand tissue regeneration that occurs in salamanders, amphibians with the ability to fully regenerate their injured limbs or organs. This a step forwards in understanding the mechanisms involved in the regeneration of tissues, in the hope that someday, we will be able to transmit this capacity to humans. 

Understanding tissue regeneration thanks to the salamander

The salamander is an amphibian family that regroups several species with the ability to fully regenerate an injured limb or organ. This ability, unique in vertebrates, is particularly studied by numerous researchers in the Axolotl (Ambystoma mexicanum), an aquatic salamander easily bred in laboratories. This species is known for its ability to remain throughout its life in the larval state, but also for its ability to regenerate its limbs and organs after amputation.

For the scientific community studying this phenomenon of tissue regeneration, the hypothesis is that this capacity is inherent in all vertebrates, but that it remains inactive in certain species, particularly in humans. A better understanding of the mechanisms involved in the axolotl could help us ‘reactivate’ this function in the hope of regenerating, at least partially, our injured organs and tissue. 

 

 

The axolotl genome, a major obstacle 

 

Unfortunately, the road is still long and full of traps. Indeed, one of the major obstacles for researchers is the axolotl genome, that is, all of its genes. Only a the complete knowledge of its genome will allow researchers to unravel the mysteries of tissue regeneration. However, the axolotl genome is ten times the size of the human genome and is very repetitive.

In a study published on the 17th of January in the scientific journal Cell Reports, scientists from Birmingham and the Women’s Hospital in Boston, USA, succeeded in gathering new information on the axolotl genome. They gathered a sort of catalogue of active genes in different tissues of the axolotl, known as the transcriptome. Concretely, the transcriptome is the full genetic information of the individual that is used in a given tissue. Complementary to the genome, the transcriptome gives valuable information about the genes active in a tissue.

 

Thus, researchers have been able to identify active genes that potentially play a role in tissue regeneration in different tissue types such as bone, cartilage, skeletal muscle, heart or blood vessels. The team was also interested in the blastemal, the mass of cells formed by axolotls shortly after limb amputation and that results in the formation of the new limb. They observed that the kazald1 gene was particularly expressed in the cells of the blastemal. The exact role of this gene, which is present in mammals, particularly in certain types of tumours, remains unknown. 

 

 

Value in sharing scientific data

 

If the catalogue of active genes in the tissues doesn’t yet reveal the secret of the axolotl’s regeneration, it is valuable data for the scientific community. “Our hope is that this new resource will make the axolotl accessible to researcher already working on this organism, but not only, also to those of other fields who might be interested”, says Jessica Whited, co-author of the study. “Unfortunately, the axolotl has long been incomprehensible to most scientists.” The team decided to make the collected data available to all via a web portal (https://portals.broadinstitute.org/axolotlomics/)  to help scientists better grasp this animal model. 

 

Hélène Bour

 

For more information:

 

A Tissue-Mapped Axolotl De Novo Transcriptome Enables Identification of Limb Regeneration Factors

New genomic tool for salamander biology could spur deeper understanding of tissue regeneration